Sam Allardyce has denied tomorrow's Carling Cup semi-final against Aston Villa will influence his future as Blackburn Rovers manager as he attempts to arrest an alarming run of form.

Blackburn have not won since beating Chelsea in the Carling Cup quarter-finals on penalties last month, a sequence of eight matches in all competitions, and their current league record stands at nine games without a victory.

Monday's anaemic display at Manchester City, which resulted in a 4-1 defeat, prompted an angry exchange at Eastlands between Allardyce and senior players and there has been growing unrest among supporters at the tactics the manager has employed since his return from heart surgery.

Blackburn have so far sold only around 11,500 tickets for the rearranged semi-final at Ewood Park although, with more than 5,000 Villa fans expected, the club are hopeful of a crowd in excess of 20,000 for the first leg. But Allardyce is adamant his position is not under threat only 13 months after he replaced Paul Ince, before ensuring Rovers' Premier League survival.

"You are always going to get rumours in the Premier League. Never a day goes by without a positive or a negative story," he said. "You are bound to get some negative scenarios going around when you have not won in a while. You just get on with your job and that is what I will do. I have no great concerns at all."

The Blackburn manager has to contend with several injury problems for the semi-final. Jason Roberts and Vince Grella have been ruled out with knee and thigh injuries respectively, and Benni McCarthy and Gaël Givet are doubtful. El Hadji Diouf is suspended following the red card he collected in the FA Cup third-round loss to Villa on 2 January.

Lars Jacobsen, the Rovers defender, has confirmed a heated inquest took place in the dressing room at City and admits the players have to react in the semi-final and Sunday's home league game against Fulham. "There were some things to be said after the game but we keep that in the dressing room," the Denmark international said. "It stays between us but of course we weren't happy with the performance," said the Denmark international.

"The semi-final is a big game for us. Any game we go into and get a result will get us going again. We have been good at home this season, we won the last time [against Villa] at Ewood, so we have to get a win there and get back on track. Then we have a home game against Fulham in the league on Sunday. We need to get a good result in the semi-final and then get some points in the Premier League. It's a massive two games."

Blackburn's chairman, John Williams, meanwhile, has revealed his confidence that David Dunn will sign a contract extension. The influential midfielder – a boyhood Rovers fan – is out of contract at the end of this season but Williams said: "It has all been very positive. Both parties want the deal to happen and negotiations are still ongoing."

For Villa tonight's tie represents a welcome return to action after their last two games, initially the first leg that was due to be played last Tuesday and Saturday's league game at Wigan, O'Neill's players are itching to be in action.

Having played on Monday, albeit enduring a 4-1 defeat at Manchester City, Blackburn at least have that competitive edge, whereas Villa are potentially well rested.

Assessing the situation, O'Neill said: "Overall, it's been a bit frustrating for us.

"The frustration stems from the fact we've travelled overnight to our last two games, and both have been called off the next day.

"However, that's the nature of things, and you just get on with it.

"Because of our postponements, and with Blackburn having played a game, they will have a bit of an advantage because they've been up and running.

"Injuries aside, that has given them an outing before tomorrow.

"But I wouldn't worry too much at this stage about advantages and disadvantages. Who knows until you get out there?"

O'Neill has no fresh injury concerns to contend with and is likely to name a full-strength side, albeit with goalkeeper Brad Guzan to continue his cup duties ahead of regular number one Brad Friedel.